摘要
毒素-抗毒素系统在原核生物中分布十分广泛,在细菌的生命活动中扮演了重要的角色,如维持水平基因转移元件的稳定性以及应对环境胁迫等。然而目前对于来自生态环境菌株中的毒素-抗毒素系统的研究仍较少。文章鉴定了自然水体环境来源的菌株ShewanellaoneidensisMR-1携带的内源性大质粒上的一对ParE-ParD家族Ⅱ型毒素-抗毒素系统SO_A0088-A0087。毒素SO_A0088在大肠杆菌以及原宿主S. oneidensis内均具有明显的细胞毒性,并导致细胞分裂存在缺陷。抗毒素SO_A0087能够完全拮抗毒素的毒性。同时,凝胶电泳迁移率实验(electrophoretic mobility shift assay,EMSA)证实抗毒素SO_A0087能够结合自身的启动子。另外,文章还通过易错突变的方法找到了毒素SO_A0088的3个毒性关键位点。
Toxin-antitoxin(TA)systems are prevalent in prokaryotes.They play important roles in cell physiological activities including maintenance of mobile genetic elements and mediation of stress responses.However,studies of TA systems in the bioelectrochemically and ecologically important strain Shewanella oneidensis are limited.In this study,we characterized SO_A0087-A0088on the megaplasmid of Shewanella oneidensis MR-1as a typical typeⅡTA system that belongs to ParE-ParD family,and the overexpression of toxin A0088leads to filamentous growth.We found that the antitoxin SO_A0087could bind to promoter of SO_A0087-A0088in vitro,and three amino acid residues of toxin SO_A0088were identified to be critical for toxicity by random mutagenesis.
作者
赵玄玉
施斐
王晓雪
ZHAO Xuanyu;SHI Fei;WANG Xiaoxue(Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences,Guangzhou 510301, China;University of Chinese Academy of Sciences, Beijing 100049, China)
出处
《热带海洋学报》
CAS
CSCD
北大核心
2018年第6期104-111,共8页
Journal of Tropical Oceanography
基金
国家自然科学基金(31500025、31500093).
